Change and predictors of change in communication, cognition, and social function between 1 and 5 years after traumatic brain injury.

OBJECTIVE: To study cognitive, communication, and social changes experienced by individuals between 1 and 5 years after traumatic brain injury (TBI).
DESIGN: Prospective cohort. SETTING AND PARTICIPANTS: TBI Model System Database with 927 eligible subjects using a cohort with complete 1- and 5-year data (N = 292). MAIN OUTCOME MEASURES: Change in Functional Independence Measure trade mark -Cognitive (FIM-Cog) items from Year 1 to Year 5 postinjury.
RESULTS: On the FIM-Cog Total score, 26% individuals improved, 61% stayed the same, and 14% worsened by more than 1 point from Year 1 to Year 5. On the 2 FIM Communication items, 19% individuals improved, 68% stayed the same, and 13% worsened by greater than 1 point. On the FIM Social Interaction item, 12% individuals improved, 76% stayed the same, and 11% worsened. On the FIM Memory and Problem Solving items, 34% individuals improved, 48% stayed the same, and 19% worsened. Several variables predicted this improvement and worsening, some of which were available at the time of injury and most were those available at 1 year postinjury. The Memory and Problem Solving items, taken together, showed fewer participants at ceiling at Year 1 and more change between Year 1 and Year 5 compared to the Communication and Social Interaction items.
CONCLUSIONS: Many individuals did not demonstrate meaningful change on FIM-Cog and its component items from Year 1 to Year 5. In particular, a high proportion of improvement was observed in Memory/Problem Solving, and worsening in Social Interaction. Demographic and functional indicators present at 1 year postinjury may be predictive of subsequent change.